Lighting devices comprising LED modules are increasingly used for lighting applications, such as for home environments. Such lighting devices are usually produced by assembling a plurality of components having different functions, such as a high power LED module (i.e. the light source), a Printed Circuit Board (PCB) containing e.g. an electronic driver for the LED module, optics, housing, and heat-sink if required.
A good thermal coupling between the LED module and the housing or the heat-sink is one of the key requirements in order to achieve a good thermal behavior of the LED module. In fact, in usual LED modules efficiency decreases for increasing operating temperature, because the forward voltage may decrease with increasing junction temperature. Moreover, the lifetime of the LED modules may be longer for lower operating temperatures, because aging usually depends strongly on the junction temperature.
A good mechanical contact between the LED module and the housing or the heat-sink is beneficial in order to achieve a good thermal coupling.
In some prior-art arrangements such thermal contact between the LED module and the housing or heat-sink is achieved by assembling the components with screws. Such screws fix and urge the PCB of the light source against the housing or heat-sink in order to ensure thermal contact. However, such arrangements may provide additional costs, because additional mechanical components (e.g. screws or washers) may be required, and a complex manual or automatic assembling process with its associated assembling time may be necessary.